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Formal Language Hierarchy

Interactive Venn diagram of the Chomsky formal language hierarchy. Visualizes the containment relationships between regular, context-free, context-sensitive, and recursively enumerable languages with security-relevant examples at each level.

By Mohamed Habib Jaouadi•September 1, 2025•
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#formal-languages
#chomsky-hierarchy
#automata
#theory
#security
The Chomsky Hierarchy: Language Classes
Nested sets showing containment. Every regular language is context-free, every CFL is context-sensitive, etc.
RegularContext-FreeContext-SensitiveRecursively Enumerablea*b*, IPsJSON, SQLaⁿbⁿcⁿPrograms
Click on a region to learn about that language class.
Key insight: Each inner class is a proper subset of the outer. A regex (Regular) cannot match balanced brackets (Context-Free). A PDA cannot verify aⁿbⁿcⁿ (Context-Sensitive).